Problem: Express your answer as a mixed number simplified to lowest terms. $13\dfrac{5}{8}-1\dfrac{9}{10} = {?}$
Answer: Find a common denominator for the fractions: $= {13\dfrac{25}{40}}-{1\dfrac{36}{40}}$ Convert ${13\dfrac{25}{40}}$ to ${12 + \dfrac{40}{40} + \dfrac{25}{40}}$ So the problem becomes: ${12\dfrac{65}{40}}-{1\dfrac{36}{40}}$ Separate the whole numbers from the fractional parts: $= {12} + {\dfrac{65}{40}} - {1} - {\dfrac{36}{40}}$ Bring the whole numbers together and the fractions together: $= {12} - {1} + {\dfrac{65}{40}} - {\dfrac{36}{40}}$ Subtract the whole numbers: $=11 + {\dfrac{65}{40}} - {\dfrac{36}{40}}$ Subtract the fractions: $= 11+\dfrac{29}{40}$ Combine the whole and fractional parts into a mixed number: $= 11\dfrac{29}{40}$